1. Field of the Invention
The invention relates generally to a method and system for the computerized radiographic analysis of bone structure. Specific applications are given for the analysis of the trabecular mass and bone pattern for the assessment of osteoporosis and as a predictor of risk of fracture. Novel techniques involve a directional analysis of the Fourier spectrum relative to many texture measures. Additional techniques include the a one-shot dual energy exposure for the assessment of bone mass while simultaneously obtaining an image for the texture analysis for bone structure.
2. Discussion of the Background
Osteoporosis is a widespread medical condition that affects about 15-20 million people in the United States and accounts for about 1.3 million new fractures per year in people greater than 45 years of age. Osteoporosis manifests as a loss in bone mass, a tendency to fracture and as a structural alteration of bone. Quantitative measures of bone mass serve as important diagnostic indicators for determining the risk of fracture and in following the progress of patients on therapy for osteoporosis. The most widely used methods of assessing bone mass are by bone mineral densitometry (BMD) that involves dual photon absorptiometry with either an x-ray or nuclear source, and quantitative computed tomography. These methods are very accurate in determining bone mass, which has been shown to be a very good predictor of fracture risk in osteoporosis. There is, however, considerable overlap of the measurements of BMD for patients with osteoporosis who have, or go on to have atraumatic fractures compared to age-matched controls who do not have, or do not go on to have, atraumatic fractures. In addition to bone mass, bone structure is probably also important in determining the mechanical strength of bone and thus fracture risk. A few preliminary studies have been performed in relating certain textural measures to bone structure.